The Trans Bay Cable (TBC) project is a submarine power transmission link (HVDC) between the cities of Pittsburgh and San Francisco, in California (USA), developed by Trans Bay Cable LLC. Prysmian has provided a “turnkey” system including the engineering, production and installation of a bipolar 200 kV DC extruded cable system with a total transmission capacity of 400 MW that runs for approximately 80 km under water and 5 km on land. The TBC project is of strategic relevance to the development of the San Francisco Bay region where the demand for power is constantly increasing. The project is designed to transmit electricity between the East Bay, which has excess electrical capacity and transmission network congestion, and the power transmission and distribution facilities in San Francisco, CA. TBC is a cost effective, energy efficient solution to address San Francisco’s needs for additional transmission capacity, while improving transmission reliability and load serving capability. In addition, it has the potential to allow for the removal of old in-city generation facilities thus eliminating related air emissions. The project was completed in 2010.